Wireless receiving system.



E. G. STALNAKBR, MINOR.

c. w. STALNAKER, GUARDIAN. WIRELESS RECEIVING SYSTEM. APPLIGATION FILED JUNE 15, 1912.

1,099,865. Patented June 9, 1914.

3 SHEETS-SHEET 1.

E. G. STALNAKER, MINOR. 0. w. STALNAKBR, GUARDIAN. WIRELESS RECEIVING SYSTEM.

APPLICATION FILED JUNE 15, 1912.

Patented June 9, 1914.

3 SHEETS-SHEET 2.

B. G. STALNAKER, MINOR.

G. W. AAAAAAAAAAAAAAAAA N. WIRELESS RECEIVING SYSTEM.

' PPPPPPPPPPPPPPPPPPPPPPPPP 1 2. 1,099,865. Patented June 9, 1914.

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UNITED STATES PATENT OFFICE.

EARL GLEN STALNAKER, OF CHICAGO, ILLINOIS; CHARLES W. STALNAKER, GUAR- DIAN OF SAID EARL GLEN STALNAKER, MINOR, ASSIGNOB TO CHARLES W. HOFF,

OF CHICAGO, ILLINOIS.

WIRELESS RECEIVING SYSTEM.

Specification of Letters Patent.

Patented June 9, 1914.

Application filed June 15, 1912. Serial No. 703,814.

To all whom it may concern Be it known that I, EARL GLEN STaL- NAKER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Wireless Receiving Systems, of which the followin is a full, clear, concise, and exact description, referencebeing had to the accompan ing drawings, forming a part of this app ication.

My invention relates to a high frequency system of transmission of energy, and particularly to the receivin apparatus for wireless telegraph or te ephone systems. With such receiving apparatus it has heretofore been customary to attune the receiving system by manual adjustments to the wave length of the wireless impulse which is to be received and to other, operative conditions. To do this, it has been necessary to have an operator continuously on duty with telephone receivers clamped to his head, in order that he might be aware of a call or message even if his receiving system was too far out of harmony with the transmitted impulses to clearly discern the latter. Upon getting this faint indication, the operator would vary the adjustments of his receiving circuits (particularly as to their inductance and capacity) until the signals became strong enough to be clearly discerned, after which the message could easily be received either by ear or by a telegraphic ticker.

The object of my invention is to provide a receiving system having an automatic tuning or adjusting arrangement which will be actuated by the incoming wireless impulse itself, without requiring the attention of an operator; which will sound an alarm so as to apprise the operator of a receivable message; and which willadjust the receiving circuit so that the incoming impulses may record themselves on a ticker, or the like, regardless of differences in the wave lengths of successive messages. I attain these objects by the construction shown in the accompanying drawings, in which- Figure 1 is a partiall diagrammatic view of the preferred embo iment of my invention, showing a receiving, alarming, and recording system. Fig. 2 is an alternative arrangement of alarming and receiving system. Fig. 3 is an enlarged view of a timing stop as used with the automatic tuner on such systems. Fig. 4'is a partially sectional elevation of the tuner. Fig. 5 is a section through Fig. 4 along the lines 55. Fig. 6 shows a lockin pawl for the latch of the tlmer. Fig. 7 s ows an alternative arrangement of the contact parts of the coil on the tuner.

. In the drawings, 2 is a conductor connectng the aerlal antennae 1 with one end of an mductive coil 3, the latter consisting preferably of a single layer of insulated wire 4 wound upon a core 5 of hard rubber. The inductance coil 3 has its insulation scraped ofi the successive turns along spiral lines 6, thus exposing these bare points to a contact brush 7 which preferably has split fingers 7 The number of spiral contact lines 6 on the coil may be as many as desired, provlded that the pitch of the spiral allows one end of the brush 7 to contact with one spiral just before the other end of the brush leaves the preceding spiral. The brush 7 is con nected by a wire 8 to a ground 9.

10 is a driving mechanism, preferably a clock or slow-speed electric motor, having a shaft 11 connected to the shaft 12 of the coil by gears 13, 14, so as to rapidly rotate the inductance coil 15 are brushes mounted on an insulated holder 16 and contacting with the surface of the inductance coil at an angle with the brush 7. Each of the brushes 15 is connected by a wire 17 to onelayer 18 of a static condenser, whose other terminals 18 are jointly connected to a conductor 19.

20 is a wave-responsive element, such as a detector or coherer, inserted between the conductor 19 and another wire 21 leading to the ground wire 8.

22 is a battery connecting the wave-responsive element 20 (which is preferably an electrolytic detector) through conductors 23 and 23..to the primary 24 of a transformer having a secondary winding 25. 26

wires 36 and 37 with a battery 38 and an electric bell 39.

40 is a switch for opening the bell circuit.

In operation, the clock 10 rotates the coil 3 continuously, thereby passing the spirally disposed contact points 6 under the contact brush 7 so as to vary the number of turns of the inductance coil 3 connected between the antenna: 1 and the ground. Likewise, the brushes 15 will vary the number of sections of the condenser 18 connected between the aerial and the' receiving circuit. Consequently, the receiving conductor system will continually be varied'both as to its inductance and as to its static capacity, thereby making it correspond successively to oscillations differing widely in their periodicity or wave-length. If the tuning coil 3 is thus rapidly rotated in the presence of a wireless impulse, the wave-responsive element 20 will respond to the said impulse when the tuning coil is in the position where the brushes 7 and 15 make the receiving circuit 1, 2, 4, 15, 17, 18, 19, 20, 21, 8 responsive to the oscillations of the said impulse. The detector 20 will then close this circuit momentarily and in doing so will also momentarily close the circuit of the battery 22 through the primary 24 of the transformer. Then the induced secondary current will actuate the relay 28, which in turn will allow the battery 29 to actuate relay 28, thereby closingthe circuit of the alarm b01139 which will call the operator. Relay 28 will also close the circuit of the magnet 35, which will attract a pivoted armature 45, thereby forcing a detent 42 between teeth of the gear 13, which detent stops the coil 3 and holds the brushes 7 and 15 in the position in which the receiving circuit is substantially attuned to, or in syntonism with, the receivable oscillations.

In practice, the impulse actuating the detector (and thereby locking the tuning system) may be of quite short duration and upon cessation of the impulse, the magnet would release its armature, thereby allowing the tune-varying coil to rotate again. To avoid this I provide a pawl or catch 43 (Fig. 5) which is engaged by the detent 42 and holds this in the latching position until released by the operator. When the detent is thus held down, the receiving circuit is kept substantially in syntonism with the wireless wave which actuates the detector, so that successive impulses may be received by the receiver 27 or recorded by the ticker 34. When the message has been received in its entirety, the operator releases the detent 4-2 by moving the catch 43to the position -13, thereby causing the tune-varier to resume its continuous changing of the inductive and electrostatic condition of the oscillation-receiving circuit.

.ment in which the of the coil, as shown in At night time, it may not be desirable to arouse the operator, hence I preferably provide a self-timing release for the detent 42, as shown in Fig. 3, in which 44 is a hollow tube (preferably of brass) having a softiron armature 45 at the end nearest to the magnet 35. This tube is partially filled with a sticky or slowly flowing liquid which will be sluggish in flowing back from one end of the tube to the other. When the magnet tilts the tube, the sudden motion will start the liquid into the end of the tube which engages the detent, where the liquid will ahnost balance the armature at the other end of the tube. On cessation of the current through the magnet, the tube or actuating member will tilt to the position shown in the dotted lines in Fig. 3; in this position it will engage the hook 46 on the detent and will tend to raise the latter, but the greater weight of the armature end of the tube will still be overbalanced by the weight of the detent. However, the liquid in the tube will now flow slowly down into the armature end of the tube until this outweighs the other end and moves the detent up against a stop 47.

While I have shown and described a responsive oscillation circuit in which the varier alters both the inductance and the capacity, I ,do not wish to be limited to this double action of the varier, nor to the particular arrangement of elements as shown in Fig. 1. For instance, by removing the brush 7 and connecting the wire 8 directly to the aerial conductor 2 (as shown by the dot ted line 18) the inductance would be left constant and the varier would only alter the capacity of the oscillation-receiving conductor. Likewise, Fig. 2 shows an arrangevarier only alters the inductance, while the capacity of the oscillalt)ion-responsive circuit is manually adjusted y a preferably insert a condenser 50 in series with the inductance coil 3, and with a primary transformer coil 51; while a variable condenser 49 is placed in series with the secondary transformer coil 52 and a relay 53, this circuit being bridged by a detector or other wave-responsive device 20'.

Instead of having the bare spots on the wire 4 in parallel spirals, as in Fig. 1, they may be arranged in lines zigzagging from one end of the coil to the other, as 1n Fi 7, so that the inductance will continua y approach and recede from its maximum. In either case the brush 7 is preferably divided into fine divisions so as to insure good contact with the bare spots on successive turns of the coil.

The brushes 15 are preferably made with contact portions COVGI'lHjL considerable arc ig. 5, so that each variable condenser 49. In this case, I

invention in its preferred embodiments, I.

do not wish to be limited to the details as shown, since numerous modifications can be made in the same without departing from the spirit of my invention. For instance, an electric motor could be substituted for the clock, and there are many other ways of arranging a receiving circuit in which the resonance or oscillation-responsiveness may be varied by varying either the inductance, or the capacity, or both.

What I claim as new and desire to cover by Letters Patent is:

1. Wireless receiving apparatus, including a receiving circuit, a tune changer for continually varying the tuning of the said re ceiving .circuit; a detent adapted to halt the said tune changer, a movable actuating member adapted to engage the said detent to move the latter out of its haltin relation to the tune changer; and mechanism actuated by the receiving circuit for simultaneously moving the detent into the position in which it halts the tune changer, and moving the actuating member out of its said actuating engagement with the said detent.

2. Wireless receiving apparatus, including a receiving circuit, a tune changer, mechanism for driving the tune changer to cause the lat-tercontinually to vary the tuning of the said receiving circuit; a gravity actuated pivoted detent adapted when in one position to lock the said driving mechanism; an actuating member mounted in proximity to the said detent and adapted when moved in one direction to raise the said detent out of its locking engagement with the said driving mechanism; a magnet adapted to be actuated by the receiving circuit and adapted, when actuated, to move the said actuating member out of its detent-lifting engagement, thereby permitting the detent to lock the said driving mechanism; and a sluggishly moving material carried by the said actuating member and adapted to move from the detent-engaging end of the said actuating member toward the other end, thereby overbalancing one end of the said actuating member and causing the latter to eifect the raising of the detent out of its lockingengagement with the driving mechanism.

3. In a high-frequency system of transmission of energy, the combination with a circuit to be tuned and a tuning apparatus therefor, of driving mechanism for continuously actuating the tuning1 apparatus; a gravity-actuated detent for alting the said driving mechanism; a pivoted actuatin member mounted in proximity to the sai detent and adapted to engage the same, the said engagement between the actuating member and the detent normally holding the latter out of locking engagement with the driving mechanism; a magnet adapted to be actuated by the wireless impulse to which the circuit is to be tuned and adapted, when actuated, to move the said actuatin member out of its normal relation with t c said detent, thereby permitting gravity to causethe said detent to halt the said driving mechanism; the said actuating member being returned by gravity upon cessation of the current through the said magnet, thereby moving the said actuating member into the position in which it tends to raise the detent out of its said locking engagement; and a sluggishly moving material carried by the said actuating member and adapted to cause the same to lift the detent out of its said engagement after a predetermined interval of time has elapsed since the said cessation of the current through the magnet.

EARL GLEN STALNAKER.

Witnesses:

M. A. SMITH, Jr., E. A. WISE. 

